Chips off the Planetary Block... ...Building Planetary Debris Disks
IN OUR own Solar System primitive bodies, such as comets and asteroids, are continually being eroded, releasing puffs and tails of debris, seeding interplanetary space with tiny dust grains. Born within the thin plane containing most of the solid mass orbiting the Sun, the trillions of dust grains form a tenuous, flattened cloud called a circumstellar disk. If gravity were the only force acting on these grains, then they would continue to orbit the Sun. However, various small but persistent influences, including radiation pressure from the Sun and drag forces, either cause grains to spiral inward to the Sun or blow them out to interstellar space. No worries. Asteroids and comets continue to fill the depleted debris disk with fresh grains. From our perspective on Earth, this dust is visible as the faint band of zodiacal light or the ‘false dawn.’ This is sunlight reflected from transitory dust in the plane of the Solar System.
KeywordsHubble Space Telescope Asteroidal Belt Extrasolar Planet Circumstellar Disk Adaptive Optic System
Unable to display preview. Download preview PDF.